Multiobjective auction-based switching-off scheme in heterogeneous networks: to bid or not to bid?

©2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The emerging data traffic demand has caused a massive deployment of network infrastructure, including Base Stations (BSs) and Small Cells (SCs), leading to increased energy consumption and expenditures. However, the network underutilization during low traffic periods enables the Mobile Network Operators (MNOs) to save energy by having their traffic served by third party SCs, thus being able to switch off their BSs. In this paper, we propose a novel market approach to foster the opportunistic utilization of the unexploited SCs capacity, where the MNOs, instead of requesting the maximum capacity to meet their highest traffic expectations, offer a set of bids requesting different resources from the third party SCs at lower costs. Motivated by the conflicting financial interests of the MNOs and the third party, the restricted capacity of the SCs that is not adequate to carry the whole traffic in multi-operator scenarios, and the necessity for energy efficient solutions, we introduce a combinatorial auction framework, which includes i) a bidding strategy, ii) a resource allocation scheme, and iii) a pricing rule. We propose a multiobjective framework as an energy and cost efficient solution for the resource allocation problem, and we provide extensive analytical and experimental results to estimate the potential energy and cost savings that can be achieved. In addition, we investigate the conditions under which the MNOs and the third party companies should take part in the proposed auction.Peer ReviewedPostprint (author's final draft

A Submodular Optimization Framework for Outage-Aware Cell Association in Heterogeneous Cellular Networks

In cellular heterogeneous networks (HetNets), offloading users to small cell base stations (SBSs) leads to a degradation in signal to interference plus noise ratio (SINR) and results in high outage probabilities for offloaded users. In this paper, we propose a novel framework to solve the cell association problem with the intention of improving user outage performance while achieving load balancing across different tiers of BSs. We formulate a combinatorial utility maximization problem with weighted BS loads that achieves proportional fairness among users and also takes into account user outage performance. A formulation of the weighting parameters is proposed to discourage assigning users to BSs with high outage probabilities. In addition, we show that the combinatorial optimization problem can be reformulated as a monotone submodular maximization problem and it can be readily solved via a greedy algorithm with lazy evaluations. The obtained solution offers a constant performance guarantee to the cell association problem. Simulation results show that our proposed approach leads to over 30% reduction in outage probabilities for offloaded users and achieves load balancing across macrocell and small cell BSs

Relay Selection Considering Successive Packets Transmission in Cooperative Communication Networks

Relay selection has been regarded as an effective method to improve the performance of cooperative communication system. However, frequent operation of relay selection can bring enormous control message overhead and thereby decrease the performance of cooperative communication. To reduce the relay selection frequency, in this paper, we propose a relay selection scheme to choose the best relay with considering successive packets transmission. In this scheme, according to the length of data packet, data transmission rate and the estimated channel state information (CSI), the best relay is selected to maximize the number of successive packets transmission under the condition that the given symbol-error-rate (SER) is kept. Finally, numerical results show that the proposed relay selection scheme can support the operation of successive packets transmission in cooperative wireless networks and that the maximum number of successive packets transmission is affected by the different network parameters, i.e., data transmission rate, packet length and Doppler frequency at one relay node

Integrated Sensing and Communication for Large Networks using Joint Detection and a Dynamic Transmission Strategy

A large network employing integrated sensing and communication (ISAC) where a single transmit signal by the base station (BS) serves both the radar and communication modes is studied. We consider bistatic detection at a passive radar and monostatic detection at the transmitting BS. The radar-mode performance is significantly more vulnerable than the communication-mode due to the double path-loss in the signal component while interferers have direct links. To combat this, we propose: 1) a novel dynamic transmission strategy (DTS), 2) joint monostatic and bistation detection via cooperation at the BS. We analyze the performance of monostatic, bistatic and joint detection. We show that bistatic detection with dense deployment of low-cost passive radars offers robustness in detection for farther off targets. Significant improvements in radar-performance can be attained with joint detection in certain scenarios, while using one strategy is beneficial in others. Our results highlight that with DTS we are able to significantly improve quality of radar detection at the cost of quantity. Further, DTS causes some performance deterioration to the communication-mode; however, the gains attained for the radar-mode are much higher. We show that joint detection and DTS together can significantly improve radar performance from a traditional radar-network

Recent Advances in Cellular D2D Communications

Device-to-device (D2D) communications have attracted a great deal of attention from researchers in recent years. It is a promising technique for offloading local traffic from cellular base stations by allowing local devices, in physical proximity, to communicate directly with each other. Furthermore, through relaying, D2D is also a promising approach to enhancing service coverage at cell edges or in black spots. However, there are many challenges to realizing the full benefits of D2D. For one, minimizing the interference between legacy cellular and D2D users operating in underlay mode is still an active research issue. With the 5th generation (5G) communication systems expected to be the main data carrier for the Internet-of-Things (IoT) paradigm, the potential role of D2D and its scalability to support massive IoT devices and their machine-centric (as opposed to human-centric) communications need to be investigated. New challenges have also arisen from new enabling technologies for D2D communications, such as non-orthogonal multiple access (NOMA) and blockchain technologies, which call for new solutions to be proposed. This edited book presents a collection of ten chapters, including one review and nine original research works on addressing many of the aforementioned challenges and beyond

Final report on the evaluation of RRM/CRRM algorithms

Deliverable public del projecte EVERESTThis deliverable provides a definition and a complete evaluation of the RRM/CRRM algorithms selected in D11 and D15, and evolved and refined on an iterative process. The evaluation will be carried out by means of simulations using the simulators provided at D07, and D14.Preprin

Efficient resource allocation algorithm for dense femtocell networks

La couverture d'intérieur pauvre et la basse capacité d'utilisateur représentent deux défis importants pour les opérateurs cellulaires. Plusieurs solutions (telles que les antennes distribuées) ont été proposées pour résoudre ces problèmes. Cependant, aucune de ces solutions ne fournit le niveau désiré de l'évolutivité et elles manquent l'aspect pratique. Pour ces raisons, une solution attrayante caractérisée par sa faible puissance et son prix faible connue sous le nom de femto-cellule a été introduite pour offrir une meilleure capacité et couverture d'utilisateur. Malgré tous les avantages provoqués par l'intégration de cette nouvelle technologie femto-cellule, plusieurs nouveaux défis ont émergé. Ces défis sont principalement présentés dans deux genres d'interférences ; connu comme interférence cross-tier et interférence co-tier. Tandis que l'impact d'interférence cross-tier (provoqué en partageant le spectre de fréquence) peut être réduit en mettant en application des algorithmes efficaces de réutilisation de fréquence, l'interférence co-tier continue à présenter un défi difficile pour les opérateurs et les chercheurs dans le domaine de réseaux cellulaires. Le déploiement non planifié et mal organisé des stations de base femto-cellule a comme conséquence une réduction radicale de la capacité d'utilisateur qui peut mener à une déconnexion des utilisateurs. L'impact de l'interférence co-tier devient plus provocant dans un déploiement dense des femto-cellule où les utilisateurs demandent des services en temps réel (par exemple, taux de données constant). Afin de réduire l'interférence co-tier, plusieurs solutions ont été proposées dans la littérature comprenant des algorithmes de contrôle de puissance, des techniques de détection avancées et des schémas d'allocation de ressources intelligentes. Dans ce projet, nous proposons une stratégie intelligente d'attribution des fréquences avec une stratégie avancée d'association de station de base femto-cellule pour les réseaux femto-cellule basés sur LTE. L'objectif des deux stratégies proposées est d'atténuer l'interférence co-tier et de réduire la probabilité de panne des utilisateurs en augmentant le nombre d'utilisateurs actifs par station de base femto-cellule. Nous montrons par simulations l'efficacité de notre solution proposée.\ud ______________________________________________________________________________ \ud MOTS-CLÉS DE L’AUTEUR : femtocell base station, interference management, resource block assignment, base station assignment, outage probability